<!DOCTYPE html>
<style>
.header {
  line-height: 40px;
}
tr {
  break-inside: avoid;
}
</style>
<div style="columns:3; column-fill: auto; height:501px; width: 600px; background-color: yellow;">
  <table cellpadding=0 cellspacing=0>
    <tr>
      <td>
        <div class="header">
          HEADER<br>HEADER
        </div>
      </td>
    </tr>
    <tr><td><div style="height: 399px; width: 1px;"></div></td></tr>
    <tr>
      <td>
        <div class="header">
          HEADER<br>HEADER
        </div>
      </td>
    </tr>
    <tr><td><div style="height: 399px; width: 1px;"></div></td></tr>
    <tr>
      <td>
        <div class="header">
          HEADER<br>HEADER
        </div>
      </td>
    </tr>
    <tr>
      <td>
        <div>Text</div>
        <div>Text</div>
        <div>Text</div>
        <table cellpadding="0" cellspacing="0" style="line-height: 20px; width: 200px;">
          <tr>
            <td style="width:64px"><strong>Col 1</strong></td>
            <td><strong>Col 2</strong></td>
            <td><strong>Col 3</strong></td>
            <td><strong>Col 4</strong></td>
            <td><strong>Col 5</strong></td>
          </tr>
          <tr>
            <td style="height:40px">0</td>
            <td>0</td>
            <td>0</td>
            <td>0</td>
            <td>0</td>
          </tr>
          <tr>
            <td style="height:40px">0</td>
            <td>0</td>
            <td>0</td>
            <td>0</td>
            <td>0</td>
          </tr>
          <tr>
            <td style="height:40px">0</td>
            <td>0</td>
            <td>0</td>
            <td>0</td>
            <td>0</td>
          </tr>
          <tr>
            <td style="height:40px">0</td>
            <td>0</td>
            <td>0</td>
            <td>0</td>
            <td>0</td>
          </tr>
        </table>
      </td>
    </tr>
  </table>
</div>
